Far-out Look At Clouds

HAMPTON — A year of data from a NASA Langley satellite gives insight into Saharan dust plumes and other drivers of the Earth's climate.

A NASA Langley satellite's first year in space will help scientists refine computer models to better predict the effects of clouds and airborne particles on global climate change.

CALIPSO, which began sending back data a year ago come Thursday, has already revealed unknown things about the distribution of aerosols in the atmosphere and polar clouds that influence the depletion of the ozone layer, said David M. Winker, the Langley scientist directing the CALIPSO mission.

Both findings will likely lead to changes in the models used to predict long-term climate patterns, Winker said Tuesday in a review of CALIPSO's first year of operations.

CALIPSO is a joint effort with the French space agency, CNES, and Hampton University.

The satellite is one of two major Earth-observing orbiters run by NASA Langley right now, at a time when concern has risen in the scientific community that money for climate science is disappearing.

The other satellite, CERES, gathers data on what is called the Earth's "radiation budget."

A National Academies of Science report earlier this year called for a renewed focus on climate science as several key satellites are reaching the end of their useful life. An Associated Press report on Tuesday revealed that the Defense Department recently pared back the climate-monitoring portion of a major satellite project. "If they don't find a way to restore it, it's going to have a major effect on climate research," Winker said Tuesday, when asked about the report.

As CALIPSO has shown, there's more to learn about climate modeling. And those models need a long string of baseline data to be effective, Winker said.

"We really need long-term data," he said.

CALIPSO now begins its second year gathering data on clouds and aerosols. An aerosol is any airborne particle that's not part of a cloud. Winker said work will shift from studying and refining the measurements CALIPSO makes to putting those measurements to use.

Some of the most interesting data and images CALIPSO sent back came from the polar regions.

CALIPSO uses LIDAR -- Light Detection and Ranging -- a remote sensing technology that uses a laser and scattered light to map and learn about clouds and aerosols. LIDAR has not been used often in satellites, and CALIPSO gives a rare three-dimensional glimpse of the atmosphere's moving parts.

The satellite has provided a much sharper picture of polar stratospheric clouds, which form in some of the coldest regions above the poles and speed the depletion of the ozone layer when they form. The data CALIPSO has gathered on the clouds will be used to update current climate models, Winker said.

The satellite is best suited to measure not only polar clouds, but also tropical cirrus clouds 50,000 feet above the Earth, the smoke from forest fires and the massive dust plumes that spread from the Sahara desert across the Atlantic Ocean. All of these things play an important role in the way Earth's atmosphere reflects and retains solar radiation, which in part dictates climate. While scientists know more about how greenhouse gases trap heat, there's more uncertainty about how aerosols and clouds deflect the sun's radiation, Winker said. *

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Year that the CALIPSO satellite has been in orbit, sending information to NASA